Various devices are used for controlling the spacing between vertebral members. These devices may be used on a temporary basis, such as during surgery when it is necessary to access the specific surfaces of the vertebral members. One technique in which this type of device may be used is during preparing the endplates of a vertebral member. The devices may also remain permanently within the patient to space the vertebral members.
It is often difficult to position the device between the vertebral members in a minimally invasive manner. A device that is small may be inserted into the patient and between the vertebral members in a minimally invasive manner. However, the small size may not be adequate to effectively space the vertebral members. A larger device may be effective to space the vertebral members, but cannot be inserted into the patient and between the vertebral members in a minimally invasive manner.
The devices may also only allow for a minimum amount of adjustability. Once placed in the patient, the devices can only be altered to a small extent. Additionally, adjusting the devices may be difficult either from an ergonomic standpoint, or from the amount of force necessary for adjustment.